锂离子电池正极材料Li_(2+2x)Ti_(1-x)Cu_x(NbO_4)_2的研究  

Study of Li_(2+2x)Ti_(1-x)Cu_x(NbO_4)_2 Used as Cathode for Lithium Ion Battery

作　　者：张玉荣[1] 王文继[1] 

机构地区：[1]福州大学化学系,福州350002

出　　处：《无机材料学报》2004年第2期349-353,共5页Journal of Inorganic Materials

基　　金：福建省青年人才科技创新基金(2001J019);福州大学人才基金(XJY-0112)

摘　　要：采用高温固相反应合成了Li2+2xTi1-xCux(NbO4)2,XRD分析表明:当x<0.8时均能得到与LiFePO4相同的橄榄石结构.电导率测定结果表明:x=0.6的合成物室温电导率最高,为1.26×10-5S/cm,且当x>0.6时合成物都表现出离子电导的特征.以x=0.6的合成物做成的待测电极与锂片组成电池,在1mol/L的LiPF6/EC+DMC(1:1)电解液中在0.5-4.6V间以0.10mA/cm2的电流密度进行电池循环测试的结果表明,该电池的首次放电比容量高达805.8mAh/g,放电平台在对Li+/Li电对为2V附近,但其可逆性及循环性均有待改善.Li2+2xTi1-xCux(NbO4)(2) was prepared by high temperature solid state reaction. XRD analysis shows that a olivine structure of LiFePO4 can be found in the composition range of x less than or equal to0.8. A.C. impedance measurements show that the initial composition of x=0.6 possesses the best conductivity of 1.26 x 10(-5) S/cm at room temperature, and that all samples with a composition of x greater than or equal to0.6 show the character of fast ion conductor. The sample with composition of x=0.6 was selected for electrode performance test, the results show that it has a very high discharge specific capacity of 805.8mAh/g with a long discharge plateau at 2.0V during the first cycle in the voltage range of 0.5similar to4.6V vs Li+/Li at 0.10mA/cm(2) rate in 1mol/L LiPF6/EC+DMC(1:1) electrolyte and that its reversibility and cycle performance need to be improved.

关 键 词：锂离子电池 正极材料 橄榄石结构 Li2+2xTi1-xCux(NbO4)2 电导率 高温固相反应 

分 类 号：TM912.2[电气工程—电力电子与电力传动] O646.54[理学—物理化学]